How many champ/elite skaters were only kids?

Well, Flatt is one. I think Weir is an only. How do you think this sport seems to select for only kids? Chan is another. National, world or Olympic Champs? Joannie Rochette is another only child. How about YuNa-does she have sibs? I'm curious as FS takes so much from parents-esp time and money. It ain't basketball!